/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 17655
 * Date: 2025-02-18
 * Time: 11:16
 */
public class test1 {
    /**
     * LeetCode 141 环形链表
     */

    public boolean hasCycle(ListNode head) {
        if(head==null || head.next==null){
            return false;
        }
        ListNode slow = head;
        ListNode fast = head.next;
        while(slow!=fast){
            if(fast==null || fast.next==null){
                return false;
            }
            slow = slow.next;
            fast = fast.next.next;
        }
        return true;
    }

    class ListNode {
      int val;
      ListNode next;
      ListNode(int x) {
          val = x;
          next = null;
      }
  }
}
